This invention relates to a MOS power amplifier circuit constructed with MOSFETs, and more particularly to a MOS power amplifier circuit capable of producing a sufficiently large output current.
Prior art includes a MOS power amplifier circuit with two MOSFETs of the same channel type and connected in series, provided at the output stage of the amplifier. One of the MOSFETs receives an input signal at the gate and the other an inverted input signal at the gate, with the result that the two MOSFETs are driven in a push-pull manner. In this prior amplifier circuit, however, if the amplitudes of the signals applied to the two MOSFETs are too small, the on-resistance of each of the two MOSFETs is unsatisfactorily decreased, resulting in an insufficient output current.